JP5578560B2 - Anterior segment measurement device - Google Patents

Description

  The present invention relates to an anterior ocular segment measuring apparatus that measures the shape of an anterior ocular tissue.

  An apparatus is known that projects slit light onto the anterior segment of the eye to be examined, obtains a cross-sectional image of the anterior segment by a Shineproof camera, and measures the shape of the anterior segment tissue (see Patent Document 1). In this case, a three-dimensional shape can be obtained by rotating the Scheimpflug camera.

  The apparatus of Patent Document 1 is configured to include a mirror that reflects slit light toward the eyes.

JP 2001-61786 A

  However, in an apparatus equipped with such a mirror, when an anterior ocular segment observation is provided behind the mirror, the direction of deviation of the optical axis is changed when the mirror is rotated. For this reason, the anterior ocular segment image is rotated during rotational imaging, making it difficult to observe the anterior ocular segment.

  In view of the above-described problems, an object of the present invention is to provide an anterior ocular segment measuring apparatus provided with a Scheimpflug camera that can suitably perform anterior ocular segment observation.

  In order to solve the above problems, the present invention is characterized by having the following configuration.

(1) A projection optical system that projects slit light onto the anterior segment of the eye to be examined, a first imaging optical system having a photographing optical axis that is inclined with respect to the projection optical axis of the projection optical system, and is based on the principle of Shine-Pluke A first imaging optical system having a photographic lens and a first imaging element arranged on the basis thereof, and imaging a cross-sectional image of the anterior eye part; System, an optical member that is disposed on an optical path of the slit projection optical system and the second imaging optical system, reflects the slit light, and transmits the reflected light from the front of the anterior segment, the slit projection optical system, and the optical member And a rotating device that integrally rotates the first imaging optical system around the projection optical axis about the projection optical axis, and an optical path disposed in the optical path of the second imaging optical system. The second imaging light generated by the rotation of the member Each having a correction optical member for correcting optical axis misalignment of an academic system, and optical correction means for rotating the correction optical member together with the rotation operation of the rotation means, and each of the images taken at a plurality of rotation angles An anterior segment tissue is measured based on an anterior segment cross-sectional image.
(2) XY alignment detection means for detecting the alignment state of the apparatus main body with respect to the eye to be examined in the XY directions based on the imaging signal output from the second imaging element, and detecting the alignment state during the rotation operation of the rotation means. (1) The anterior ocular segment measuring device according to (1).
(3) The anterior segment measuring apparatus according to (2), further comprising an automatic alignment unit that moves the apparatus main body with respect to the eye to be examined based on a detection result of the XY alignment detection unit.
(4) The anterior segment measurement apparatus according to (3), wherein the rotation unit integrally rotates the slit projection optical system, the optical member, the first imaging optical system, and the correction optical member.

  In the anterior ocular segment measuring apparatus provided with the Scheimpflug camera, the anterior ocular segment observation can be suitably performed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an external view of an anterior segment measuring apparatus according to this embodiment. This apparatus is provided with a base 2, a face support unit 4 attached to the base 2, a movable base 6 movably provided on the base 2, and a movable base 6, which will be described later. A measurement unit (device main body) 8 that houses the optical system is provided. The measurement unit (device main body) 8 is provided with a monitor 70 for displaying various information such as an observation image of the eye E to be examined and measurement results. The movable table 6 is moved on the base 2 in the left-right direction (X direction) and the front-rear direction (Z direction) by operating the joystick 12. The measuring unit 8 is moved in the vertical direction (Y direction) by the drive mechanism 17 including a motor or the like when the rotary knob 12a is rotated. The movable table 6 is provided with an operation unit 85 on which switches for performing various settings are arranged.

  FIG. 2 is a perspective view of the optical system of the anterior segment measuring apparatus according to the present embodiment. FIG. 3 is a diagram showing a configuration when the optical system of the anterior segment measuring apparatus according to the present embodiment is viewed from the lateral direction.

  The present optical system has a slit projection optical system 20 that projects slit light onto the anterior segment of the eye to be examined and an imaging optical axis that is inclined with respect to the slit projection optical axis, and is an imaging lens that is arranged based on the principle of Shine-Pluke. And an imaging optical system 30 having an imaging device, a fixation target projection optical system 40, an alignment projection optical system 50, and a working distance for detecting an alignment state in the working distance (Z) direction of the measuring unit 8 with respect to the eye to be examined. The optical system is roughly divided into a detection optical system 60 (60a, 60b), a kerato projection optical system 45 for projecting a corneal shape measurement index onto the cornea, and an anterior ocular segment front imaging optical system 90 for imaging an anterior ocular segment front image. The A light source that illuminates the anterior segment Ea with infrared light is disposed outside the detection optical system 60. The above optical system is built in the measurement unit 8.

<Slit projection optical system>
The slit projection optical system 20 (see FIG. 3) includes a light source 21, a condenser lens 22, a slit plate 23, a total reflection mirror 25, a projection lens 26, and a dichroic mirror 24. The dichroic mirror 24 is an optical member that reflects slit light and transmits other light. As the light source 21, for example, a light source that emits light (blue light) having a center wavelength of about 470 nm and a wavelength region of about 460 to 490 nm is used. The slit plate 23 is disposed at a position conjugate with the anterior eye part (for example, near the apex of the cornea).

  The light beam emitted from the light source 21 is condensed by the condenser lens 22 and illuminates the slit plate 23. The light beam limited to a thin slit shape by the slit plate 23 is reflected by the total reflection mirror 25 and then condensed by the projection lens 26. Thereafter, the light beam is reflected by the dichroic mirror 24 and then projected to the eye E as slit light. Thereby, the translucent body (cornea, anterior chamber, crystalline lens, etc.) of the anterior segment of the eye to be examined is illuminated in the form of being light-cut by the slit light.

<Slit cross-section imaging optical system>
The imaging optical system 30 includes a two-dimensional imaging element 35 and an imaging lens 33 that guides reflected light from the anterior segment by the slit projection optical system 20 to the imaging element 35, and based on the Shine-Pluke principle It is the structure which images a cross-sectional image. That is, the imaging optical system 30 is arranged such that its optical axis (imaging optical axis) intersects with the optical axis of the projection optical system 20 at a predetermined angle, and the optical section of the projection image by the projection optical system 20 and the cornea Ec. The lens system including the cornea (the cornea and the imaging lens 33) and the imaging surface of the imaging element 35 are disposed in a Shine-Pluke relationship. A filter 32 that transmits only light (blue light) that is emitted from the light source 21 and used to capture a cross-sectional image of the anterior segment is disposed in front of the lens 33 (on the eye E side).

<Fixed target projection optical system>
The fixation target projection optical system 40 includes a visible light source (for example, LED) 41 and a relay lens 42. Light emitted from the light source 41 is relay lens 42, dichroic mirror 92, correction optical member 91, dichroic mirror 24, The light is projected to the eye E through the opening 66b.

<Alignment index projection optical system>
The alignment index projection optical system 50 includes a near-infrared light source 51 for alignment, a projection lens 52, a polarizing beam splitter 53, and a dichroic mirror 92. After the light emitted from the light source 51 is converted into a parallel light beam by the projection lens 52, Reflected by the polarization beam splitter 53. Thereafter, the alignment light is reflected by the dichroic mirror 92, travels toward the eye E along the optical axis L1, and is used to project an alignment index onto the cornea Ec. The index projected on the cornea (see B in FIG. 5) is used for alignment in the XY direction with respect to the eye E (for example, automatic alignment, alignment detection, manual alignment, etc.).

<Working distance detection optical system>
The detection optical system 60 projects a projection optical system (index projection optical system) 60 a that projects alignment light for Z detection from an oblique direction toward the eye cornea Ec to be examined, and a light receiving element that receives the alignment light from the projection optical system 60 a. And a light receiving optical system 60b that receives light from an oblique direction. The light projecting optical system 60 a and the light receiving optical system 60 b are disposed behind the kerato projection optical system 45.

  The light projecting optical system 60a includes an infrared light source 61, a reflecting prism 62, and a light projecting lens 63, and is an index for Z detection through a first hole (not shown) provided in the kerato projection optical system 45. Infrared light is projected onto the cornea Ec from an oblique direction. Note that the infrared light source 61 of the light projecting optical system 60 a emits infrared light having a wavelength different from that of the light source 51 of the projection optical system 50.

  The light receiving optical system 60b includes a position detection element (for example, a line CCD) 69, a reflecting prism 68, and a light receiving lens 67, and projects light through a second hole (not shown) provided in the kerato projection optical system 45. An index image formed on the cornea Ec is detected by the system 60a (receives infrared light from the light source 61 reflected by the cornea Ec). The light projecting optical system 60a and the light receiving optical system 60b are arranged in the vertical direction for convenience of explanation, but are actually inclined at a predetermined angle (for example, 25 °) with respect to the horizontal direction and the optical axis L1. Are arranged symmetrically. Thus, the kerato projection optical system 45 can measure the corneal curvature in the horizontal direction.

<Kerato projection optical system>
The kerato projection optical system 45 has a ring-shaped light source (not shown) arranged in the ring opening 66 around the optical axis L1, and projects a multiple ring index on the cornea Ec to form a corneal shape (curvature distribution, astigmatism axis). Angle, etc.). Further, the ring opening 66 has a plurality of ring-shaped openings 66a having different diameters formed in the peripheral portion, and has an opening 66b used as an observation optical path in the center.

  As the light source, for example, an LED that emits infrared light or visible light is used. The kerato projection optical system 45 may be a placido index projection optical system.

<Anterior Eye Front Imaging Optical System>
The anterior ocular segment imaging optical system 90 includes a dichroic mirror 92, a polarizing beam splitter 53, a field lens 94, a plane mirror 95, a plane mirror 96, a filter 97, an imaging lens 98, and a two-dimensional imaging device 99, and the eye to be examined. Used to capture an anterior ocular segment front image.

  Further, between the dichroic mirror 24 and the dichroic mirror 92, a correction optical member 91 (for example, a prism) 91 for correcting an optical axis shift caused by the rotation of the dichroic mirror 24 is provided. The correction optical member 91 is substantially the same thickness as the dichroic mirror 24 and has substantially the same refractive index. The correction optical member 91 is disposed so as to be symmetric with respect to the dichroic mirror 24 and the optical axis L1. In other words, the correction optical member 91 is disposed so as to correct the optical axis deviation due to the rotation of the dichroic mirror 24.

  Reflected light from the front of the anterior segment by the projection optical system 45, the projection optical system 50, and the anterior segment illumination optical system (not shown) is dichroic mirror 24, correction optical member 91, dichroic mirror 92, polarization beam splitter 53, field of view. An image is formed on the two-dimensional image sensor 99 through the lens 94, the plane mirror 95, the plane mirror 96, the filter 97, and the imaging lens 98.

  Further, the present apparatus is provided with a rotating means (rotating mechanism 100) for rotating the slit projection optical system 20 and the imaging optical system 30 described above around the slit projection optical axis L1. .

  FIG. 4 is a diagram illustrating an example of the configuration of the rotation mechanism 100. The cylindrical portion 110 has a cylindrical structure with a hollow inside, and incorporates the dichroic mirror 24 and the correction optical member 91. A part of the projection optical system 20 (a projection unit including a light source 21, a condensing lens 22, a slit plate 23, a total reflection mirror 25, and a projection lens 26) and the imaging optical system 30 are fixed to the outer peripheral surface of the cylindrical portion 110. Has been.

  The cylinder part 110 is rotatably attached to a first rotary bearing (for example, a ball bearing) 115 fixed to the apparatus main body. Moreover, the cylinder part 110 is rotatably attached to the second rotary bearing 118 fixed to the apparatus main body via the connecting member 120. A kerato projection optical system 45 and a working distance index projection optical system 60 are fixed to the second rotary bearing 118. Further, a sensor 111 (see FIG. 3) that detects an initial rotation position of the cylindrical portion 110 is provided.

  Below the fixation target projection optical system 40, a drive unit 101 (for example, a pulse motor), a shaft 102 connected to a rotation shaft of the drive unit 101, and a first pulley 103 directly connected to the shaft 102 are arranged. Yes. On the other hand, the second pulley 107 is directly connected to the end of the cylindrical portion 110 on the image sensor 99 side. A belt 105 is hung on the first pulley 103 and the second pulley 107.

  With the above configuration, when the drive unit 101 is driven, the first pulley 103 is rotated. Then, the rotational force of the first pulley 103 is transmitted to the second pulley 107 via the belt 105, and the second pulley 107 is rotated. Then, due to the rotation of the second pulley 107, the cylindrical portion 110 is rotated around the optical axis L1 with respect to the apparatus main body (for example, in the A direction). In addition, the imaging optical system 30 is rotated around the optical axis L1 as the cylindrical portion 110 rotates.

  For example, as shown in FIG. 4A, which is a device diagram after the start of rotation, from FIG. 4A, which is a device diagram before the start of rotation (initial rotation position), the rotation unit (projection optical system 20 and imaging optics). The unit 200 including the system 30 is rotated with respect to the apparatus main body. That is, when the drive unit 101 is driven, the slit projection optical system 20 and the imaging optical system 30 are rotated and moved independently with respect to the kerato projection optical system 45 and the detection optical system 60.

  In other words, the kerato projection optical system 45 and the detection optical system 60 are arranged at positions independent of the rotational movement of the rotation unit 200 and do not rotate with the rotation unit 200. The detection optical system 60 detects the alignment state in the Z direction while being fixed at a predetermined position. The kerato projection optical system 45 projects the index onto the cornea while being fixed at a predetermined position.

  Next, the control system will be described. The control unit 80 controls the entire apparatus and calculates measurement results. The control unit 80 includes a light source 21, a light source 41, a light source 51, a light source 61, a drive mechanism 17, a drive unit 101, a sensor 111, an image sensor 35, a position detector 69, a two-dimensional image sensor 99, a projection optical system 45, and a monitor 70. Are connected to the memory 86 and the like. The control unit 80 is connected to an operation unit 85 for performing various input operations. In addition to various control programs, the memory 86 stores a software program for the control unit 80 to calculate a corneal curvature and the like. Further, the memory 86 obtains a three-dimensional position of a predetermined anterior segment tissue based on each anterior segment cross-sectional image captured at a plurality of rotation angles and rotation angle information at the time of capturing, and the shape of the tissue A software program for measuring is stored.

  For example, the operation unit 85 issues a switching signal for switching between a first mode in which a measurement is performed by taking a cross-sectional image of the anterior segment and a second mode in which a corneal shape (curvature distribution, astigmatic axis angle, etc.) is measured. Mode switching means (mode switching switch 85a) is provided. The operation unit 85 may be a general-purpose interface such as a mouse as an operation input unit, or may be a touch panel.

  Based on the switching signal from the mode selector switch 85a, the control unit 80 captures each anterior segment sectional image at a plurality of rotation angles by the slit projection optical system 20 and the imaging optical system 30 in the first mode, The shape of the tissue is measured. In the second mode, the kerato projection optical system 45 projects a ring index onto the cornea Ec to measure the shape of the corneal surface.

  The operation of the apparatus having the above configuration will be described. First, a case where the first mode is set will be described. The examiner moves the measurement unit 8 in the XYZ directions using the joystick 12 while watching the alignment state of the subject's eye displayed on the monitor 70 (see FIG. 5). At this time, the examiner causes the eye E to fixate a fixation target (not shown). In FIG. 5, a reticle LT is a mark displayed electronically as an alignment reference.

  When the measurement unit 8 is moved as described above and the index image B is detected, the control unit 80 detects the coordinate position of the index image B as a substantially corneal apex based on the imaging signal from the imaging element 99, Detect misalignment direction / deviation amount in XY direction. And the control part 80 controls the drive of the drive part 17, and moves the measurement part 8 to an XY direction so that alignment deviation may enter into the predetermined alignment tolerance | permissible_range.

  Further, the control unit 80 detects the misalignment direction / deviation amount in the Z direction based on the light reception signal from the position detection element 69. Then, the control unit 80 moves the measurement unit 8 in the Z direction so that the misalignment in the Z direction falls within a predetermined alignment allowable range.

  When the alignment displacement in the XYZ directions satisfies the alignment completion condition by the alignment operation described above, the control unit 80 determines that the alignment in the XYZ directions is matched, and issues a trigger signal for starting measurement.

<Shooting cross-sectional images>
When the trigger signal for starting measurement is output, the control unit 80 turns on the light source 21. As the light source 21 is turned on, the driving unit 101 is driven to rotate the rotating unit 200 (the correction optical member 91, the slit projection optical system 20, and the imaging optical system 30) about the optical axis L1. When the light source 21 is turned on, the anterior segment is cut by slit light. The scattered light from the anterior segment that has been cut by the slit light is directed to the imaging optical system 30, and a cross-sectional image is taken by the imaging element 35. At this time, the control unit 80 causes the memory 86 to store the captured image output from the image sensor 35 at every predetermined rotation angle in synchronization with the number of pulses of the driving unit 101. Also, information on the shooting angle is stored in association with the shot image. It should be noted that the photographing light quantity of the light source 21 is controlled to be constant during rotational photographing.

  In addition, during rotation shooting, the control unit 80 detects the alignment state in the Z direction using the detection optical system 60, and drives based on the detection result so that the positional deviation of the eye E during shooting is corrected. 17 is controlled. Thus, Z tracking is performed at every predetermined rotation angle even during rotational shooting. Of course, the control unit 80 may drive the drive unit 17 based on the alignment detection result in the XY directions to perform XY tracking. In this case, the control unit 80 may correct the positional deviation of each cross-sectional image by image processing based on the alignment detection result for each rotation angle.

  Since a photographic image for the entire circumference can be obtained by half rotation, the number of photographic images is preferably 18 (rotation every 10 degrees) or more. More preferably, the number is 36 or more (every 5 degrees of rotation angle). In the present embodiment, when the slit light width is set to 80 μm, 80 captured images captured at every rotation angle of 2.25 degrees are automatically stored in the memory 86 so that the three-dimensional analysis can be performed as accurately as possible. The rotation angle may be fixed, but a configuration that can be arbitrarily set is preferable.

  Note that the slit projection optical system 20 and the imaging optical system 30 are placed at an initial rotation angle (for example, a 0 degree position) before photographing. Whether or not the projection optical system 20 and the imaging optical system 30 are at the initial positions is detected by the sensor 111. The return to the initial position is performed when the apparatus is activated or by pressing a reset switch (not shown) on the operation unit. In addition, when the three-dimensional imaging is finished, the driving unit 101 is driven, and the projection optical system 20 and the imaging optical system 30 are arranged at the initial positions.

  When shooting is completed, the control unit 80 calls all the shot images stored in the memory 86 and the rotation angle information thereof, constructs the shot images using a software program, and saves them in the memory 86.

<Kerato photography>
When the mode selector switch 85a for the second mode is selected by the examiner, the control unit 80 switches the mode from the first mode to the second mode. The control unit 80 may automatically switch from the first mode to the second mode. When switched to the second mode, the control unit 80 turns on the light source in the ring opening 66 and projects the ring target to the eye to be examined.

  FIG. 5 is a diagram illustrating an anterior ocular segment observation screen on which an anterior ocular segment image captured by the image sensor 99 is displayed. Also in the second mode, the control unit 80 controls the driving of the driving unit 17 based on the alignment detection result, and performs automatic alignment in the XYZ directions. In this case, smooth measurement is possible by continuing the tracking in the first mode. When the alignment is completed, the ring index R1 by the projection optical system 45 and the ring index R2 on the outside thereof are further displayed on the anterior ocular segment observation screen.

  When a predetermined trigger signal is issued in the state where the alignment is completed as described above, the control unit 80 captures an anterior segment image using the image sensor 99. Then, the control unit 80 acquires an anterior ocular segment image including the ring indexes R1 and R2 as a still image based on the imaging signal output from the imaging element 99 and stores the acquired anterior eye image in the memory 86.

  When the measurement is completed as described above, the control unit 80 determines the curvature of the corneal surface, the curvature of the corneal surface, the corneal thickness, the curvature of the front surface of the lens, the curvature of the back surface of the lens, the lens thickness, the anterior chamber based on the anterior segment cross-sectional image. Calculate the measured values of each tissue such as depth. The control unit 80 also determines the shape of the corneal surface based on the index image R1 / R2 in the anterior segment image stored in the memory 86 (for example, the corneal curvature in the strong main meridian direction and the weak main meridian direction, the astigmatic axis of the cornea). Angle, etc.). The measurement result by the kerato index uses a reflected image as compared with the measurement result by the anterior segment cross-sectional image, so the measurement accuracy is good (because the influence of distortion is small). These measurement results are stored in the memory 86 and output to the monitor 70.

  As described above, the anterior segment is accurately measured by providing the Z alignment detection system in the device that captures the anterior segment sectional image at each rotational position by the rotation of the slit projection system and the Shine peak camera. In addition, it is possible to correct the deviation between the cross-sectional images by detecting the alignment in the Z direction even during the photographing of the cross-sectional images. The tracking may be performed while rotating the Shine peak camera. Alternatively, the rotational movement of the Shine peak camera may be temporarily stopped, and after the tracking is completed, photographing may be started again.

  In addition, the apparatus for capturing an anterior segment cross-sectional image further includes a ring index projection system and an anterior segment front imaging system, and when the shape of the corneal surface is measured, alignment is performed using a Z alignment detection system. Thus, the shape of the corneal surface can be measured with high accuracy. This is particularly effective when multiple ring indexes are projected over a wide range.

  Further, since the detection optical system 60 is fixed to the apparatus main body independently of the rotational movement of the rotation unit 200, alignment detection in the Z direction at the time of capturing a cross-sectional image or a front image can be accurately performed. On the contrary, in the case of the configuration in which the detection optical system 60 is rotated, the positional relationship between the detection optical system 60 and the apparatus main body may fluctuate due to vibration of the rotation operation or the like. Then, an alignment error between the detection optical system 60 and the optical axis of the eye to be inspected may occur, and a detection error in detecting the alignment in the Z direction may occur.

  In addition, in the case where the measurement is performed in the order from the first mode for capturing the cross-sectional image to the second mode for capturing the kerato index as described above, when the Z alignment detection is performed in the second mode, the slit is formed after the end of the cross-sectional imaging. It is possible to avoid the trouble of rotating the projection system and the Shine peak camera to return the Z-direction alignment detection system to the initial position.

  In the present embodiment, the second mode measurement is performed after the end of the first mode in the present embodiment. However, the first mode measurement may be performed after the second mode measurement. .

<Correction optical member 91>
Next, the correction optical member 91 will be described. The anterior ocular segment reflected light from the projection optical system 45, the projection optical system 50, and the anterior ocular segment illumination system (not shown) passes through the optical path of the dichroic mirror 24, the correction optical member 91, and the dichroic mirror 92 to the two-dimensional imaging element 99. Imaged. At this time, the optical axis L1 becomes the optical axis L1 ′ deflected by the dichroic mirror 24, but the deviation is returned by the correction optical member 91.

  Here, when the dichroic mirror 24 is rotated together with the rotation of the slit projection optical system 20, the direction of deviation of the optical axis L1 is changed. Here, as shown in FIG. 6, when there is no correction optical member 91, the imaging optical axis of the anterior segment is moved on the imaging element 99 according to the rotational position. That is, during the rotation shooting, the anterior ocular segment image and the alignment index are rotated on the image sensor 99, making it difficult to observe the anterior ocular segment and detect the alignment.

  Therefore, in the present embodiment, as shown in FIG. 7, the correction optical member 91 is rotated around the optical axis L1 as the dichroic mirror 24 rotates, so that the deviation of the optical axis is always corrected, and the rotational position Regardless, the imaging optical axis of the anterior segment is returned to the optical axis L1.

  In this way, the imaging optical axis on the imaging device 99 is constant regardless of the rotational position. Thereby, it can be avoided that the anterior segment image and the alignment index are rotated by the rotation of the dichroic mirror 24.

  Therefore, the examiner can satisfactorily observe the anterior segment image during rotational imaging. In addition, alignment detection / tracking in the XY directions during rotational shooting can be performed.

  In the present invention, the dichroic mirror 24 and the correction optical member 91 are integrally rotated using the common drive unit 101. However, the present invention is not limited to this. For example, a drive unit dedicated to the correction optical member may be provided, and the correction optical member 91 may be rotated in synchronization with the rotation of the dichroic mirror 24. However, in this case, it is necessary to change the arrangement of the optical system because a separate driving unit is required and a space for arranging the driving unit is required. For this reason, it may lead to an increase in the size of the apparatus and an extra cost, so that the configuration of the present invention is better.

  Further, the correction optical member may be disposed in the optical path of the imaging optical system 90. For example, the correction optical member may be disposed between the dichroic mirror 24 and the eye E, or may be a dichroic. The structure arrange | positioned between the mirror 92-the image pick-up element 99 may be sufficient.

  In the above description, the dichroic mirror 24 is used as an optical member that reflects light from the slit projection optical system and guides it to the eye to be inspected and transmits reflected light from the front of the anterior eye part and guides it to the two-dimensional image sensor 99. However, the present invention is not limited to this, and a half mirror may be used.

  When detecting the alignment in the XY direction with respect to the eye to be examined, detection may be performed by image processing based on the anterior segment image. For example, a feature portion (pupil, iris, etc.) in the anterior segment image may be extracted by image processing to detect movement of the feature portion.

It is an external view of the anterior segment measuring apparatus according to the present embodiment. It is a perspective view of the optical system of the anterior ocular segment measuring apparatus according to the present embodiment. It is a figure which shows a structure when the optical system of the anterior eye part measuring device which concerns on this embodiment is seen from a horizontal direction. It is a figure which shows an example of a structure of a rotation mechanism. It is a figure which shows the anterior ocular segment observation screen on which the anterior ocular segment image was displayed. It is a figure which shows that an anterior ocular segment imaging optical axis moves when there is no correction optical member. It is a figure which shows that the deflection | deviation of an imaging optical axis is correct | amended by the correction | amendment optical member.

DESCRIPTION OF SYMBOLS 8 Measurement part 12 Joystick 20 Slit projection optical system 24 Dichroic mirror 30 Imaging optical system 33 Imaging lens 35 Two-dimensional image sensor 40 Fixation target projection optical system 45 Kerato projection optical system 50 Alignment projection optical system 60 Working distance detection optical system 70 Monitor DESCRIPTION OF SYMBOLS 80 Control part 85 Operation part 86 Memory 90 Front eye part front imaging optical system 91 Correction | amendment optical member 99 Two-dimensional image sensor 100 Rotation mechanism 101 Drive part 200 Rotation unit

Claims (4)

A projection optical system that projects slit light onto the anterior segment of the eye to be examined;
A first imaging optical system having a photographic optical axis inclined with respect to the projection optical axis of the projection optical system, having a photographic lens and a first imaging element arranged on the basis of the Shine-Pluke principle, A first imaging optical system for capturing a cross-sectional image of
A second imaging optical system for imaging the front image of the anterior segment by a second imaging element from the front direction;
An optical member that is disposed on the optical path of the slit projection optical system and the second imaging optical system, reflects the slit light, and transmits the reflected light from the front of the anterior segment;
Rotating means for integrally rotating the slit projection optical system, the optical member, and the first imaging optical system about the projection optical axis around the axis,
A device body comprising:
A correction optical member that is disposed in the optical path of the second imaging optical system and corrects an optical axis shift of the second imaging optical system caused by the rotation of the optical member; An optical correction means for rotating the correction optical member,
An anterior ocular segment measuring apparatus that measures an anterior ocular tissue based on cross-sectional images of an anterior ocular segment imaged at a plurality of rotation angles.   XY alignment detection means for detecting the alignment state of the apparatus main body with respect to the eye to be examined in the X and Y directions based on the imaging signal output from the second imaging element, and detecting the alignment state during the rotation operation of the rotation means. The anterior ocular segment measuring apparatus according to claim 1.   3. The anterior ocular segment measuring apparatus according to claim 2, further comprising automatic alignment means for moving the apparatus main body with respect to the eye to be examined based on a detection result of the XY alignment detection means.   4. The anterior ocular segment measuring apparatus according to claim 3, wherein the rotating unit integrally rotates the slit projection optical system, the optical member, the first imaging optical system, and the correction optical member.

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